Theatre: The droning of Fay Weldon

The Four Alice Bakers

Birmingham Rep

Lift Off

Royal Court Upstairs, London

Shockheaded Peter

Lyric, London

In her new play, Fay Weldon has come up with a new and sinister hate figure. It isn't the genetic scientist or the chatshow host or the daughter who accuses her father of sexual abuse, though all these characters appear prominently. Her new scary monster is never actually glimpsed in .

This figure is the anonymous TV researcher who digs up enough personal details about the unsuspecting guests on the "Harry Harper Ethical Show" to expose them to the prurient scorn of millions. Thanks to the surprising omniscience of his researcher, Harry Harper knows more about Professor Baker and his family than they do themselves. He is about to reveal (and I'm not giving it away, it's in the Birmingham Rep leaflet) that Baker's three daughters are clones of his wife.

Michael Cashman seizes the role of Harper, the smarmy TV host, who puts Baker, a genetic scientist, in the "hot seat", with demonic glee. Try to imagine Jeremy Paxman doing a Joel Grey in Cabaret. A song and dance moraliser, he waggles an accusing index finger at any un-PC remark and boogies on down to the commercial jingles from the show's sponsor.

Weldon's grasp of science doesn't impress us the way Michael Frayn's does in Copenhagen. Nor does her grasp of the mechanics of broadcasting impress us the way Stephen Poliakoff's does in Talk of the City. It's easy enough to do the fanfare opening of a TV show, the swirling lights and apocalyptic music, as Cashman walks down the illuminated staircase to soak up the audience's applause. In TV terms, that's pure showbiz. The tough part is to sustain the illusion of a TV programme taking place within a play. It requires an assured grasp of the distinct rhythms of the two media, and an ability to shift our focus between what can be seen by the imaginary TV audience and what can't. In on-stage/off-stage dramas, the energy lies in the shuttling between the two.

The director, Bill Alexander, places cameras and monitors round the edge of the stage, but the cameras don't follow the action, and what's displayed on the monitors resembles closed-circuit TV. After an entertaining, splashy opening, Alexander's production implodes, as we realise it's easier to believe in the most technical scientific advances, that are currently occupying Professor Baker, than in these characters or their situation.

Ruari Murchison's designs split the Birmingham Rep stage into three areas: the snazzy TV studio; the hospitality suite that's suspended in the air like a capacious lift; and a circular tower that revolves to let us travel back in time to catch glimpses of the Baker's family life. Centre stage, we have a high-backed leather swivel chair, where first Professor Baker, then his wife, then his eldest daughter, then his middle daughter, and then his youngest daughter, face Cashman's questions. Structurally, the play is a bore.

Baker, the rumpled scientist (David Hargreaves), worked with Francis Crick on DNA structures at Cambridge. That was when he fell in love with Alice (Diane Fletcher). We know Alice was an English rose because she announces, in a line that characterises the play's level of dialogue: "I am what you would call an English rose." The three daughters also announce their characters as if filling in questionnaires. One may or may not have been abused by their father. One may or may not be a lesbian. One may or may not really be a man.

Topical subjects then, but it never lives as drama. You feel Fay Weldon, who has written 20 TV plays, has watched more bad TV than good theatre. On stage, there's nowhere to go. After the interval it quickly becomes apparent that there may be four Alice Bakers, but there's no second act. As the play limps towards its premature conclusion, the spirits begin to soar.

In a week in which issues of race rapidly boiled down to a few iconic images of Stephen or Doreen and Neville Lawrence on the one hand and the five suspects on the other, Roy Williams's Lift Off was a salutary antidote. Ultz, the designer, sits the audience in a single row round a concrete stage that's raised to eye-level, like a boxing ring. Grafitti is daubed on the walls. Here we watch the friendship between a black boy and a white boy as it runs from primary school through to adulthood.

Awareness of race is always there, but only when they fall out does it become a focus for their anger. At school, Mal, the young black (Ashley Chin) teases Tone, the young white (Sid Mitchell) that he really wants to be black. They both pick on another black kid. When they are adults and fall out, Mal (Michael Price) challenges Tone (Alex Walkinshaw) to call him a "nigger". He would feel better if his ex-friend hated him.

Williams's gift for undermining cliches, and poking around in tricky subjects, makes Lift Off refreshingly complicated and contradictory. Indhu Rubasingham's production has easygoing yet vigorous performances from both the younger and older casts. They're adept at punching out Williams's convincing colloquial dialogue. The joshing strikes us as typical of the tangy emotional lives that we can believe in.

Peter Brook's maxim was that he could take an empty space and call it a stage. The creators of Shockheaded Peter revel in all the aspects of theatre that Brook swept away with that single statement: front cloth, proscenium arch, fourth wall, footlights, cut-outs, plunging perspectives, pop-ups and make-up. They celebrate the vanished world of illusion.

Co-directors Phelim McDermott and Julian Crouch return to the Lyric, where they staged their Angela Carter-inspired Cinderella, with this "junk opera" that mixes cabaret with macabre stories from Heinrich Hoffmann's 1844 Struwwelpeter. Shockheaded Peter matches the talents of the high- pitched cherubic crooner, Martyn Jacques, as he moves from honeyed tones to savage shrieks, with the histrionic narration of Julian Bleach, whose saturnine make-up might have been applied by a house painter.

Everything gets elongated, from finger nails and hair to pauses and screams. The central story of two parents who murder a child that continues to grow in their imagination, gets stretched through a dozen other stories. Over the 100 minutes, without an interval, momentum is never at a premium. But the ceaseless visual inventiveness turns the cosy nostalgic world of children's theatre to self-consciously dark and gruesome ends. As cut- outs of the children's graves rise from the floor, everything that was once seen to be deadly about theatre turns out to be deadly in an entirely new and invigorating way. Peter Brook might approve.

`': Birmingham Rep (0121 236 4455), to 13 March. `Lift Off': Royal Court Upstairs, WC2 (0171 565 5000), to 13 March. `Shockheaded Peter': Lyric ,W6 (0181 741 2311), to 10 April.